Android 4.4.2 Update
I created a new recovery installable patch to enable WiFi tethering for the the AT&T Galaxy S3 with the stock i747UCUFNE4 rom; it should work on any stock FNE4 Rom. Bluetooth tethering may also work with this patch, but I am not sure for all cases. This patch updates 'framework-res.apk' in your /system/framework folder.
As before, I recommend creating a backup patch using your original framework-res.apk. Make a copy of the patch file "Tether_i747UCUFNE4.zip" and change the name to something like "Orig_i747UCUFNE4.zip". Open this new zip (using Win-Zip or 7-zip) and replace 'framework-res.apk' with the one from the /system/framework folder on your device.
Copy both zips to your external sdcard. Re-boot to recovery, flash Tether_i747UCUFNE4.zip, re-boot, and verify that it works. If you have problems, you can always restore your system by rebooting to recovery and installing the Orig_i747UCUFNE4.zip.
Link:
Tether_i747UCUFNE4.zip